盐溶液中膨润土膨胀变形的分形模型

发布时间：2018-03-29 05:07

本文选题：膨润土　切入点：膨胀变形　出处：《岩土力学》2017年01期

【摘要】：当压实膨润土在蒸馏水中膨胀后,施加于膨润土颗粒上的有效应力通常被认为是外部施加的荷载,而当膨润土在盐溶液中膨胀时,膨润土颗粒所承受的有效应力还包括由孔隙水渗透吸力所引起的渗透应力。而压缩膨润土的蒙脱石孔隙比e_m与膨润土颗粒承受的有效应力p之间满足分形关系,该关系可用来计算膨润土的膨胀变形。通过对压实膨润土在盐溶液中颗粒的分散情况以及颗粒表面的分形特性,推导出该渗透应力的表达式,进而得出膨润土颗粒所承受的有效应力。将所提出的有效应力代入分形模型中,计算GMZ01和MX-80膨润土在不同浓度NaCl溶液中的膨胀变形,将现有的两种膨润土膨胀试验结果与模型计算结果对比,发现具有较好的吻合度,在蒸馏水以及各浓度的盐溶液中膨润土的膨胀变形都可采用统一的e_m-p曲线表示,表明提出的有效应力符合膨润土颗粒在盐溶液中的实际受力情况。分形模型为研究膨润土在盐溶液中的膨胀性质提供了有效的计算方法。
[Abstract]:When the compacted bentonite expands in distilled water, the effective stress applied to the bentonite particles is generally considered to be an external load, while when the bentonite expands in salt solution, The effective stress of bentonite particles also includes the osmotic stress caused by pore water permeability, while the fractal relationship between the effective stress p of bentonite particles and the ratio of montmorillonite porosity em of compressed bentonite to the effective stress p of bentonite particles is satisfied. The relation can be used to calculate the swelling deformation of bentonite. The expression of the osmotic stress is derived through the dispersion of the particles in salt solution and the fractal characteristics of the particle surface. Then the effective stress of bentonite particles is obtained. The proposed effective stress is added to the fractal model to calculate the swelling deformation of GMZ01 and MX-80 bentonite in NaCl solution with different concentrations. Comparing the results of two kinds of bentonite expansion tests with the results of model calculation, it is found that there is a good agreement. The expansion deformation of bentonite in distilled water and salt solution of different concentrations can be expressed by uniform e_m-p curve. It is shown that the proposed effective stress accords with the actual stress of bentonite particles in salt solution and the fractal model provides an effective calculation method for studying the swelling properties of bentonite in salt solution.
【作者单位】：安徽工业大学建筑工程学院;上海交通大学船舶海洋与建筑工程学院;
【基金】：国家自然科学基金重点项目(No.41630633),国家自然科学基金项目(No.41272318,No.41472251) 安徽省教育厅资助重点项目(No.kJ2013A052)~~
【分类号】：TU443

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